Surface texturing has many applications in electron sources, electric bonding, solar cells, optics and display devices. One of the most commonly used technologies for surface texturing is ion beam sputtering. The details of this process are described in Cone Formation as a Result of Whisker Growth on Ion Bombarded Metal Surfaces, G. K. Wehner, J. Vac. Sci. Technol. A3(4), pp. 1821-1834 (1985) and Cone Formation on Metal Targets During Sputtering, G. K. Wehner, J. Appl. Phys., Vol. 42, No. 3, pp. 1145-1149 (Mar. 1, 1971), which are hereby incorporated by reference herein, which teach that a cone (micro-tip) structure may be produced by using an ion source for etching a material, such as copper, after it has been seeded with a second material, such as molybdenum. An improvement upon this process is the subject of the above cross-referenced patent application, wherein a dual ion beam system is utilized to efficiently control the ion beam sputtering process.
For many applications, it is required that the surface textured structure be uniform in terms of the density, height and shape of the resultant cones. Additionally, for mass production manufacturing, the process should be controllable and repeatable. However, the above-noted surface texturing process using ion beam sources is difficult to control, and the structures of the cones are not as uniform as many applications require, such as for flat panel display devices.
Thus, there is a need in the art for a surface texturing process that is controllable, repeatable, and produces a uniformity of resultant cones.